The present invention relates to a suspension layout using a steering gear frame, and more particularly, to a suspension layout using a steering gear frame in which an assembly for an independent power steering system is integrated into a single structure.
A sub-frame for a vehicle is typically mounted in a lower portion of the engine compartment; that is, to a lower front area of the vehicle frame along the width direction of the vehicle. The sub-frame interconnects the suspension system and the vehicle frame. The sub-frame also supports a steering gear box assembly.
Since the sub-frame determines the overall strength of the vehicle frame to a great extent, it is necessary that the sub-frame possess a strength of at least a predetermined amount. Also, the sub-frame must be able to securely support structural elements of the suspension system that are connected to the sub-frame on opposite ends thereof.
Conventional sub-frames are typically made by bolting or welding together press-formed plates to provide a closed cross-section member. Separate brackets are bolted or welded on to secure a steering box assembly along the sub-frame member. However, the conventional sub-frame presents drawbacks in size and weight when made of sufficient strength. Also, the overall time required for manufacture is unnecessarily increased with the mounting of the steering gear box assembly to the sub-frame in a separate process. Finally, the large number of parts needed for the steering gear box assembly increases overall manufacturing costs and makes for a complicated structure in the area where the steering gear box assembly is provided.
In one preferred embodiment, the present invention provides a suspension layout using a steering gear frame comprising a sub-frame and steering apparatus assembly. The sub-frame includes a plurality of side members, which are provided in a longitudinal direction of a vehicle frame and at a predetermined distance from each other in a direction along a width of the vehicle. The sub-frame also includes a cross member extending in a direction along the width of the vehicle and fixedly connected to the side members. The steering apparatus assembly includes steering gear motors that are provided on each side member and operate such that the steering rods undergo rectilinear motion. A steering transmitting assembly cooperates with the rods to convert the rectilinear motion of the rods to rotational motion of knuckles.
In an alternative embodiment, a vehicle suspension layout comprises first and second side frame members with a cross member extending between and rigidly securing together the side frame members. The side members and cross member together form at least a part of a sub-frame. First and second steering gear motors are disposed each on one side member in a lengthwise direction thereof. First and second steering assemblies disposed on the sub-frame, one each cooperating with one steering gear motor to transmit steering forces independently to knuckles associated with vehicle wheels. Preferably, the steering gear motors are disposed in indentations formed in the side members. Also, the steering assemblies may comprise a link element hingedly connected to a tie rod with the link element pivotably mounted on the cross member. The link member is hingedly connected to a rod of the steering gear opposite the tie rod, and the tie rod is configured for connection to the knuckle opposite the link member.